The present invention relates generally to a new and unique construction for an easy-open, tear-apart package useful for releasably holding a plurality of containers together as a single unit. The invention relates more specifically to a tear-open package comprises a film of material, which shrinks upon application of heat thereto to releasably retain and to constrictively captivate a plurality of containers encompassed thereby.
Packaging a plurality of containers together as a single unit can be achieved in a wide variety of ways and methods commonly known to individuals skilled in the relevant art. Such ways and methods include, for example, encompassing containers in cardboard boxes and trays to form a "case" or a "twelve pack," encircling the outer peripheries of the containers with a flexible, resilient material to form a container carrier, and surrounding the containers with a flexible, resilient material that shrinks upon the application of heat or an appropriately directed force.
One of the more popular methods of packaging a plurality of containers is to surround the containers with a sheet of heat shrinkable polymetric film material which shrinks upon application of heat to conform to the exterior configuration defined by the plurality of containers, thereby captivating the same. A pattern of slits or perforations is supplied to the sheet of polymetric film material either before the heat shrinking process, as in the method disclosed in the patent of Limousin, U.S. Pat. No. 4,586,312, or after the heat shrinking process, as in the method disclosed in the patent of Kennedy, U.S. Pat. No. 3,016,131, so that sheet may be ruptured to release the containers.
Use of each of these various methods results in a differently formed and similarly functioning container or package. Specifically, the patent of Burgess, U.S. Pat. No. 3,488,913, discloses a method of producing a shrink wrapped package having two distinct film regions which overlap each other, meet edge to edge, or are separated. To open the package, one must pull one film region away from the other. However, use of this packaging method requires utilization of a separate tray to act as a bottom support for the containers and as a pivot point about which the film regions can be moved. The necessity of the separate tray adds to the cost of and time needed for implementation of the method.
The patent of Limousin, U.S. Pat. No. 4,586,312, discloses a method for producing a heat shrinkable package having a break-away access panel to allow removal of the containers. This method produces a package having a removable longitudinal strip making the containers retained in the package accessible from the package exterior. To produce the removable strip, perforations or slits must be located on the wrapped package before the heat shrinking process takes place. In order to prevent rupturing of the slits during the heat shrinking process, the portion of the package bearing the slits is placed facing a conveyor belt which moves the package through a heat tunnel or other apparatus for applying thermal energy to the shrink wrap. This method may not be desirable in some applications due to the particular sensitivity of the method to orientation of the package.
The patent of Lems et al, U.S. Pat. No. 4,919,265, discloses a method for making a film encased package. In this method, the package is formed by spirally applying a stretch film to the exterior surfaces of a plurality of containers. However, this method requires the use of sub-packages, and does not seem to be useful in creating a package of individual, free containers.